serial polling

using System;
using System.IO.Ports;

class PortDataReceived
{

    public static void Main()
    {
        SerialPort portA = new SerialPort("COM7");

        portA.BaudRate = 9600;
        portA.Parity = Parity.None;
        portA.StopBits = StopBits.One;
        portA.DataBits = 8;
        portA.Handshake = Handshake.None;

        portA.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandlerA);

        portA.Open();

        SerialPort portB = new SerialPort("COM9");

        portB.BaudRate = 9600;
        portB.Parity = Parity.None;
        portB.StopBits = StopBits.One;
        portB.DataBits = 8;
        portB.Handshake = Handshake.None;

        portB.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandlerB);

        portB.Open();

        Console.WriteLine("Press any key to continue...");
        Console.WriteLine();

        DataObject data = DataObject.Instance;

        int keyIn = 0;
        do
        {
            // Check if any key pressed, read it into while-controlling variable
            if (Console.KeyAvailable)
                keyIn = Console.Read();

            // Poll our channel A data
            if (!string.IsNullOrEmpty(data.DataA))
            {
                Console.WriteLine(String.Format("Received data {0} on channel A. This is a(n) {1}", data.DataA, data.TypeA()));
                data.DataA = "";
            }

            // Poll our channel B data
            if (!string.IsNullOrEmpty(data.DataB))
            {
                Console.WriteLine(String.Format("Received data {0} on channel B. This is a(n) {1}", data.DataB, data.TypeB()));
                data.DataB = "";
            }

            data.DoSomethingCool();
            data.DoSomethingBoring();

           // Stop looping when keyIn is no longer 0
        }while (keyIn == 0);


        portA.Close();
        portB.Close();
    }

    private static void DataReceivedHandlerA(
                        object sender,
                        SerialDataReceivedEventArgs e)
    {
        SerialPort sp = (SerialPort)sender;
        DataObject.Instance.DataA = sp.ReadExisting();
    }
    private static void DataReceivedHandlerB(
                    object sender,
                    SerialDataReceivedEventArgs e)
    {
        SerialPort sp = (SerialPort)sender;
        DataObject.Instance.DataB = sp.ReadExisting();
    }


    public class DataObject
    {
        private static volatile DataObject instance;
        private static object syncRoot = new Object();

        /// <summary>
        /// Singleton implementation
        /// <see cref="http://msdn.microsoft.com/en-us/library/ff650316.aspx"/>
        /// </summary>
        public static DataObject Instance
        {
            get
            {
                if (instance == null)
                {
                    lock (syncRoot)
                    {
                        if (instance == null)
                        {
                            instance = new DataObject();
                        }
                    }
                }

                return instance;
            }
        }

        // Constructor
        private DataObject() { }


        // Fields - use these to abstract the process or initialize
        private string _dataA = "";
        private string _dataB = "";

        // Properties
        public string DataA {
            get { return _dataA; }
            set { _dataA = value; }
        }
        public string DataB
        {
            get { return _dataB; }
            set { _dataB = value; }
        }
        // Methods
        public void DoSomethingCool()
        {
            // Implement something cool
        }

        public void DoSomethingBoring()
        {
            // Implement something boring
        }

        public string TypeA()
        {
            int result;
            if (int.TryParse(DataA, out result))
                return "Integer";
            else
                return "String";
        }

        public string TypeB()
        {
            int result;
            if (int.TryParse(DataB, out result))
                return "Integer";
            else
                return "String";
        }
    }
}